1 // Copyright 2007 all rights reserved; see LICENSE file for BSD-style license
3 package edu.berkeley.sbp.meta;
4 import edu.berkeley.sbp.util.*;
5 import edu.berkeley.sbp.*;
8 import java.lang.reflect.*;
9 import java.lang.ref.*;
12 * Currently this class exports only static methods to create repetitions;
13 * there are no public instance methods or constructors
15 class Repeat extends Union {
17 public Repeat(final Element e, boolean zeroOkay, boolean manyOkay, Object tag) {
18 this(e, zeroOkay, manyOkay, null, false, tag); }
19 public Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, Object tag) {
20 this(e, zeroOkay, manyOkay, separator, false, tag); }
21 protected Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal, Object tag) {
22 this(e, zeroOkay, manyOkay, separator, maximal, tag, null); }
23 protected Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal, Object tag, Atom follow) {
28 ? (maximal ? "**" : "*")
29 : (maximal ? "++" : "+")))
35 Sequence s = Sequence.create(new Repeat(e, zeroOkay, manyOkay,
36 separator, maximal, tag, null)).followedBy(follow);
41 add(Sequence.create(tag, new Element[] { }, null).followedBy(follow));
42 if (!(zeroOkay && manyOkay))
43 add(Sequence.create(tag, new Element[] { e }, null).followedBy(follow));
45 // FEATURE: stringify ~[]* as ...
46 if (zeroOkay && manyOkay && separator!=null) {
47 add(Sequence.create(many1(e, separator, tag)).followedBy(follow));
49 } else if (manyOkay) {
51 add(Sequence.create(tag,
52 new Element[] { Repeat.this, e },
53 new boolean[] { false, false },
54 new boolean[] { true, false }));
56 add(Sequence.create(tag,
57 new Element[] { Repeat.this, separator, e },
58 new boolean[] { false, true, false },
59 new boolean[] { true, false, false }
65 public static class Maximal extends Repeat {
66 public Maximal(final Element e, boolean zeroOkay, boolean manyOkay, final Atom separator, Object tag) {
67 super(e, zeroOkay, manyOkay, separator, true, tag, (Atom)separator.complement());
68 if (zeroOkay && separator != null)
69 throw new RuntimeException("cannot create a maximal repetition of zero or more items with a separator (yet): " + this);
71 public Maximal(final Atom e, boolean zeroOkay, boolean manyOkay, Object tag) {
72 super(e, zeroOkay, manyOkay, null, true, tag, (Atom)e.complement());
76 /** repeat zero or one times */
77 public static Element maybe(Element e) { return new Repeat(e, true, false, null, null); }
78 public static Element maybe(Element e, Object tag) { return new Repeat(e, true, false, null, tag); }
79 /** repeat zero or more times */
80 public static Element many0(Element e) { return new Repeat(e, true, true, null, null); }
81 public static Element many0(Element e, Object tag) { return new Repeat(e, true, true, null, tag); }
82 /** repeat zero or more times, separated by <tt>sep</tt> */
83 public static Element many0(Element e, Element sep) { return new Repeat(e, true, true, sep, null); }
84 public static Element many0(Element e, Element sep, Object tag) { return new Repeat(e, true, true, sep, tag); }
85 /** repeat one or more times */
86 public static Element many1(Element e) { return new Repeat(e, false, true, null, null); }
87 public static Element many1(Element e, Object tag) { return new Repeat(e, false, true, null, tag); }
88 /** repeat one or more times, separated by <tt>sep</tt> */
89 public static Element many1(Element e, Element sep) { return new Repeat(e, false, true, sep, null); }
90 public static Element many1(Element e, Element sep, Object tag) { return new Repeat(e, false, true, sep, tag); }
92 /** repeat zero or more times, matching a maximal sequence of atoms */
93 public static Element maximal0(Atom e) { return new Repeat.Maximal(e, true, true, null); }
94 public static Element maximal0(Atom e, Object tag) { return new Repeat.Maximal(e, true, true, tag); }
95 /** repeat one or more times, matching a maximal sequence of atoms */
96 public static Element maximal1(Atom e) { return new Repeat.Maximal(e, false, true, null); }
97 public static Element maximal1(Atom e, Object tag) { return new Repeat.Maximal(e, false, true, tag); }
98 /** repeat one or more times, separated by an atom <tt>sep</tt>, matching a maximal sequence */
99 public static Element maximal1(Element e, Atom sep) { return new Repeat.Maximal(e, false, true, sep, null); }
100 public static Element maximal1(Element e, Atom sep, Object tag) { return new Repeat.Maximal(e, false, true, sep, tag); }
102 public static Element repeatMaximal(Atom e, boolean zero, boolean many, Object tag) {
103 return new Repeat.Maximal(e, zero, many, tag); }
104 public static Element repeatMaximal(Element e, boolean zero, boolean many, Atom sep, Object tag) {
105 return new Repeat.Maximal(e, zero, many, sep, tag); }
106 public static Element repeat(Element e, boolean zero, boolean many, Object tag) {
107 return new Repeat(e, zero, many, tag); }
108 public static Element repeat(Element e, boolean zero, boolean many, Element sep, Object tag) {
109 return new Repeat(e, zero, many, sep, tag); }